as we know that in 2017 many ICO were successful (at least reached softcap) and of course the market cap was also very high at the time,
ICO was a buzzword at that time. Blame it on the media propaganda, no regulatory authorities poking their noses into the market as to what fueled that bull run.
so it proves that many people are interested to investing in cryptocurrency,
Or that many wannabe "venture capitalists" got burnt trying to turn 100$ into 1000$ and ended up getting their money locked up in a shitcoin that is worth 0.1$ now. Being an investment banker is not a get-rich-quick scheme.
but now where do these investors go?
Gone rekt or waiting for market to raise so they can sell some of that bagload of shitcoin.
because now the market cap is down and many ICO or IEO are failing (not reaching softcap), are investors no longer interested to investing in cryptocurrency? if yes, where are they investing now? or is there a more profitable investment than investing in cryptocurrency for now?
I would have said bitcoin but its beyond the point of reach at this point. If bitcoin falls b 1k-2k USD then buy it at the dip for long term. You could also look into the more traditional markets like stocks, commodities, metals.
In short, every market has this up and down cycle. Its important to enjoy the bull and suffer the bear. Only then can you be a successful trader.